PROF. J. TAFT said he had never used amalgam as a filling material. Oxyphosphate acts differently in different hands. Had seen an oxyphosphate last eighteen years. It should not be used close to the gum, or in proximal positions. Is one of the very best materials for porcelain inlays. A _good_ oxyphosphate will last as long as an _ordinary_ gold filling. He uses it very often as an intermediate filling material. Much is due to the manner in which it is mixed. It should be thoroughly mixed. Some will granulate when used immediately, but if it is worked between the fingers, it becomes quite plastic and in that condition it is better and easier used. Heat accelerates, while cold retards setting. DR. J. R. CALLAHAN asked if either the oxychloride or the oxyphosphate hardened the dentine. DR. J. S. CASSIDY said oxychloride would harden by dehydration; much depends upon the healthy condition of the saliva. Mechanical abrasion has little to do with its loss. Chemical action is its chief cause. More loss takes place in mouths whose saliva is vitiated by putrefaction than by fermentation. PROF. TAFT said cleanliness is very important in mouths containing cement fillings. DR. H. J. MCKELLOPS spoke upon the oxyphosphates and their effect upon the dentine. If inserted in cavities and allowed to remain a year or so, when taken out the dentine will be found very hard and a gold filling may be inserted. It is one of the best materials for filling, and is especially applicable for children's teeth. Eructions from the stomach are very destructive to phosphate fillings. He says oxychloride is not the best root filling, especially in small roots. The mercury of amalgam will render a pulpless tooth very brittle. PROF. H. A. SMITH:—Good manipulation is requisite to success in plastic fillings; the parts should be thoroughly combined. He had seen a large crown oxyphosphate filling which had been inserted eight years ago, in Germany. They were good filling materials, but had their place.